1. Field
The subject invention is in the fields of equipment and apparatus used for mooring boats and ships and of facilities used for loading and unloading what is carried by the vessels, i.e. the payloads, in particular vehicles and passengers. More particularly, it is in these fields as applicable to ferry boats for which it is especially important that mooring, loading and unloading be done expeditiously.
2. Prior Art
With the conventional prior art in these fields, as applied to ferry boats, the boats come into the dock end first guided by pilings or wingwalls, are held in place by mooring lines and/or vessel propulsion, and a ramp hinged on the dock facility is lowered to the main deck of the boat for unloading payload and then raised before the boat departs. The ramps are usually no more than two vehicle lanes wide while the decks of the boats are often several lanes wide. This situation sets up requirements that the boat be fitted with inter-deck ramps and that deck space be devoted specifically to provision for convergence of the several lanes to the one or two used for loading and unloading. Meeting these requirements limits the number of decks which can be feasibly used and lowers the ratio of payload space to total deck space of the boats using such mooring and ramp systems, thus limiting the traffic flow rate capability of the ferry system, especially relative to the speeds and displacements of the boats used in the system. A second aspect of conventional mooring and ramp systems which limits the traffic flow rate capability is that each boat must be unloaded and loaded in sequence, requiring significantly more time per turn around than would be required if loading and unloading were done simultaneously.
Accordingly, the primary objective of the subject invention is that it enhance the traffic flow rate capability of a ferry system. Secondary objectives which contribute to achieving meeting the primary objective are that: (1) the mooring and ramp system be unaffected by changes in water level caused by tides or other factors, (2) the mooring and ramp system facilitates simultaneous loading and unloading of boats, and (3) it facilitates use of multi-deck ferry boats.